Handpiece for dental engines.



PATENTED AUG. 1 3, 1907.

J. H. SPRINGLE. EANDPIBUE POR DENTAL ENGINES.

APPLICATION FILED 0012.26, 1904.

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ma Nosms PETERS co.. WASHINGTON, n. c.

JEFFREY HALE SPRINGLE, OF MONTREAL, QUEBEC, CANADA.

HANDPIECE FOR DENTAL ENGINES.

Specification of Letters Patent.

Patented Aug. 13, 1907.

Application filed October 26,1904. Serial No. 230,096.

To all whom it may concern:

Be it known that II, JEFFREY HALE SrniNeLn, of the city of Montreal, District of Montreal, and Province of Quebec, Dominion of Canada, have invented certain new and useful Improvements in Handpieces for Deni tal Engines; and I do hereby declare that the following is a full, clear, and exact description of the same.

My invention relates particularly to hand pieces for dental engines and it has for its object to render the same ascptic.

The invention may be said, briely, to consist of a separable handle portion or shell and a separable driving shaft the points of connection of the members of each of which are adapted to be opened for the purpose of exposing the interior of those parts which are incontact while the members are assembled, thus enabling such parts to be sterilized, or otherwise thoroughly cleansed.

For full comprehension, however, of the invention reference must be had to the accompanying drawings forming a part of this specification in which like symbols indicate the same parts, and wherein,

Figure l is a side elevation of a hand piece for a dental engine constructed according to my invention, Fig. 2 is a longitudinal sectional view thereof; Figs. 3 and 4 are detail perspective views of the`dismembered parts of the carrying end of the driven shaft, Figs.v 5 and (i are similar views of the outer bearing end of the shell or handle, and Figs. 7 and S are end and side elevations rcspectivelyof the shank of the tool.

The driving shal t is as usual in three parts, b, e and f, the part b being connected to the usual flexible shaft (not shown) as formerly. The member, -b, has a tapped axial boring, c, in its forward end into which the diminished and screw-threadedrear end, d, of member, e, is screwed, the forward end of the latter member being also formed with a tapped axial boring, g, into which the diminished and screw-threaded rear end of member,

' f, is screwed.

The shell or hand piece proper comprises two tubular members o and q connected together by the externally screw-threaded rear end of the member, q being screwed into an internally screw-threaded collar, p, formed integrally with the forward end of the member o. The forward end of the member, q, is also externally screwthreaded and carries an internally screw-threaded coupling sleeve r.

My invention has reference to the forward end of the shaft member, f, (which carries the tool) the shell s, t, coupled to the shell member q by the coupling sleeve i* and inclosing the said shaft member f, and to the frictional contact between the shell member q and shaft member e.

According to my invention the free end of the shaft member f is made tubular and one side thereof is diadapted to register in recesses, Zi, in the axial edges presented by the end of the shaft; while one end of this semitubular piece, Z, has axially projecting teeth, Zo, adapted to engage in notches i in the shaft end. This end of the shaft member, f, also presents a cylindrical block, f, which assists in steadying the parts when they are fitted together.

The interior of the semi tubular end of the shaft member, f, and the removable semi-tubular piece, Z, are each formed with screw threaded sections g the threads whereof are in the same spiral lines, to enable the shank, n, of the tool, which is formed with correspondingly mutilated threads to be engaged therewith, when the semi tubular piece, Z, is set in place and the tubular end of the shaft member f is complete. These parts of the shaft member, f, are retained in engagement by the shell member which also constitutes a feature of my invention. This improved shell member is divided longitudinally into two parts, s and t, the part t having a pair of pointed lugs, u, and a short cylindrical bearing, o, while the part s is formed with a pair of notches, sf, adapted to receive the pointed lugs u and in conjunction therewith retain the outer ends of these parts of the shell against displacement away from one another, while the coupling ring, r, prevents both longitudinal and lateral displacements of the rear ends of these parts.

The perimeter of the shaft member, c, is formed with a pair of circumferential grooves, a, and the interior of the shelf member q is formed with a pair of coinciding annular grooves, y. These coinciding pairs of grooves constitute raceways for two series of balls which reduce the friction between the driving shaft and the handle.

The main advantage of this construction is that the tool carrying member and the shell inclosingthe same, which are the parts most liable te become infected and not heretofore capable of being thoroughly cleansed,

can be readily disconnected from each other and sterilized or otherwise rendered aseptic, while the antifriction bearing between the shell or handle and the shaft enables the same to run more freely.

What I claim is as follows:-

l. In a dental hand piece a tool carrying member made in separable parts constructed to receive the tool between rhein and retain such tool against longitudinal displacement, and detachable means whereby the said separable parts are secured together' for the purpose set forth.

2. In a dental hand piece, a tool carrying shaft meinber the free end whereof is tubular and a portion whereof is separable therefrom, such separable portieri and the remainder of such shaft end being formed with coacting engaging devices adapted to engage and retain the tool; and means for detachably securing the said parts of the shaft end together.

ln a dental hand piece the combination with a tool the shank whereof is formed with a mutilated thread, of a shaft member one end whereof is tubular and consists of separable semi-tubular coacting parts, a portion vided therefrom, as at Z, and formed with lugs, j, j, l 0fv the interior of each 0f which is formed with a mutilated thread, the mutilated thread of one part coinciding with that of the other, and such separable parts conjointly receiving the shank of the tool between them, and displaeeable means securing such separable parts against displacement relatively to one another.

4. In a dental hand piece the combination with a tool carrying member, of a shell inclosing the said member and divided longitudinally into separate parts, the said parts having means for the purpose of securing' them together.

5. In a dental hand piece, the combination with a tool carrying member, of a tubular shell inelosing the said member and divided longitudinally into separate parts one of such parts having diagonal teeth upon the edge thereof near one end and the edge of the other part hav- .ing diagonal notches therein to receive the diagonal teeth, and an interiorly screw-threaded sleeve screwed upon the opposite ends of the said tubular parts for the purpose set forth.

G. In a tool carrying member made in separable parts constructed to receive -and retain the tool between them I and detachable means whereby the said parts are secured together such detachable means consisting of a shell inclosing' the said member and divided longitudinally into separate parts, and having means whereby'the said parts are detachably secured together.

7. A tool carrying member made in separable parts constructed to receive and retain the tool between them, and a tubular shell inclosing the said member and divided longitudinally into separate parts one of such parts having diagonal teeth upon the edge thereof near one end and the edge of the other part having diagonal notches therein to receive the diagonal teeth, and an interiorly screw threaded sleeve screwed upon the other ends of the said tubular parts for the purpose set forth.

In testimony whereof, I have signed my name to this specification in the presence ot' two subscribing witnesses.

' JEFFREY HALE SPRINGLE.

Witnesses z P. GonMAN, FRED J. SEARS. 

